I carry mcnett's tenacious tape for field repairs. This is a relatively inexpensive flexible nylon backed tape with excellent adhesive.
Fortunately, I haven't had to patch my sleeping pad yet (exped synmat), but I have used the tape successfully on pants, bags, and a tarp. It's worked for me on nylon, nylon/cotton, silnylon, and even wool. I was going to follow up on the pants by restitching the hole, but the tenacious tape has held up for 6 months and multiple washes without any problem.
Might be worth a look.